RecruitingBehavioural interventionThe Effects of a Low Glycemic Load Diet on Dysglycemia and Body Composition in Adults With Cystic Fibrosis-Related DiabetesThis study will evalute the effect of a low glycemic load (LGL diet on dysglycemia, insulin requirements, DXA-derived body composition, gastrointestinal symptoms and quality of life measures in adults with cystic fibrosis-related diabetes (CFRD). We will use continuous glucose monitors (CGM) to assess the LGL diet both in a controlled setting (via a meal delivery company) and in free-living conditions.